Neurogenesis occurs throughout adult life in rat dentate gyrus. Factors and mechanisms of adult neurogenesis regulation are not well known.
Vitamin E deficiency has been found to deliver a neurogenetic potential in rat dorsal root ganglia. To determine whether the role of
tocopherols in adult neurogenesis may be generalized to the central nervous system, changes in adult rat dentate gyrus neurogenesis were investigated in
vitamin E deficiency. Neurogenesis was quantitatively studied by determination of the density of
5-bromo-2'-deoxyuridine (
BrdU)-labeled cells and by determination of the total number of cells in the granule cell layer. The
BrdU-labeled cells were immunocytochemically characterized by demonstration of neuronal marker
calbindin D28K. The following results were found: (1) the volume of the granule layer increased in controls from 1 to 5 months of age, mainly due to cell density decrease; (2) the volume increased by a similar amount in
vitamin E-deficient rats, mainly because of an increase in cell number; (3)
BrdU-positive cells were more numerous in
vitamin E-deficient rats in comparison to age-matched controls; (4) the increase in proliferated cells was located in the hilus and in the plexiform layer. This study confirms that neurogenesis occurs within adult dentate gyrus and demonstrates that this process is enhanced in
vitamin E deficiency. This finding indicates that
vitamin E may be an exogenous factor regulating adult neurogenesis.